The number of extreme climate events in Germany has at least doubled in the last fifty years and they are likely to become more frequent in the future. These extreme events have the potential to alter regional flora and fauna. The warm and dry weather in 2018, not only caused an unusual hot summer in Germany but also lead to low Elbe river discharge, and as a consequence, affected the water level in Cuxhaven and the biogeochemistry of the German Bight. Several selected monitoring stations in the German Bight captured the changes for water level, salinity and water temperature in 2018. For all selected stations, salinity showed a significant increase in 2018 with respect to the confidence intervals or maximum value analysis. Except for the most northern station (FINO3), maximum water temperatures at all stations were recorded in 2018. Contrary to most measured parameters, dissolved oxygen increased in 2018 contrary to expectations. However, dissolved oxygen is also very much influenced by biology, either production or consumption and thus several factors influences its distribution. For future studies, especially for the explanation of dissolved oxygen, the effects of other rivers and the new plants in German Bight can be used. At the river mouth, the observed changes were more prominent than at the distant stations like FINO3. The results also showed that missing data in the permanent sampling stations from which the data were taken had a distinct negative effect on the analysis quality and should be avoided in these long-term time series.